Surgical depth gauge



FIG. 1 is a perspective view of the surgical depth gauge of the present invention showing the new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is an elevational view thereof, as viewed from any side; and,

FIG. 4 is a bottom plan view thereof.

The broken line showing of is included for the purpose of illustrating environment and forms no part of the claimed design. 

The ornamental design for a surgical depth gauge, as shown and described. 